Cabrillo National Monument - Nature and Science

Cabrillo National Monument by National Parks Service

Statue of Juan Rodriguez Cabrillo along the coastal-sage covered ridgeline with a view of the city of San Diego and the entrance to the San Diego Bay. (NPS Photo) Cabrillo National Monument (NM) is located in San Diego, California on the Point Loma peninsula. The peninsula encompasses more than 267 hectares (660 acres) of native habitat and the monument is located on 67 hectares (160 acres) of the southern-most point. The peninsula is bordered by the Pacific Ocean on the west, the San Diego Bay on the east, and an urban development on the north. It also is home to regionally diminishing stands of coastal sage scrub habitat.

At the time Juan Rodríguez Cabrillo sailed into San Diego Bay in 1542, a rich diversity of life was present that ranged from desert cactus to moisture-loving algae; tarantulas to sea slugs, and gray foxes to sea lions. Approximately 3,000 Native Americans lived in the San Diego area at that time. The Kumeyaay, or Diegueños according to the Spanish accounts, lived simply in the environment but likely impacted the landscape through the use of fire. Today, due largely to the impacts of European colonization, and centuries of growth and development, the habitat Cabrillo saw is now among the rarest in the world. Although only a remnant of that biologically diverse ecosystem remains, it is well worth visiting and protecting. This unique diversity of plants and animals occurs here because Cabrillo NM lies at the southern-most extent of some plant and animal ranges, and the northern-most extent of others.

Cabrillo NM has a Mediterranean climate characterized by warm, dry summers and cool, mild winters. Weather data is recorded for San Diego at Lindburgh Field (the airport) which is directly across the bay from the monument. The average annual temperature is 17.8 o C (64 o F) and the average annual rainfall is 24 cm (9.5 inches). Rainfall is concentrated in the winter, from November to April, but the amount can drastically change year to year from 8.6 cm (3.4 in.) to 49.3 cm (19.4 in.). This variability in rainfall causes certain types of plants to thrive one year and barely survive another. Nature makes up for this lack of rain when cold air from the ocean meets the balmy air on the land and dense fogs roll in. The fog adds moisture to allow species requiring more water to coexist with the desert plants and animals. The ocean also keeps air temperatures mild year-round, which allows heat-loving cactus to grow next to evergreen shrubs common in cooler climates, salamanders to walk past sunning desert snakes, and mosses to grow in the cool shade, a stone's throw from where parched lichen cling to dry, hot boulders.

In addition to the unusual climate, Cabrillo NM hosts many uncommon species of birds because of its location along the Pacific flyway. Over 200 species of birds have been recorded at Cabrillo NM, including land, shore, and sea birds. It is not uncommon to see a tiny ruby-crowned kinglet hopping through a bush on land, huge brown pelicans flying silently low in formation over the ocean waves, and a solitary red-tailed hawk soaring overhead searching for its next meal.

On the west side of the park, a rocky interface between the land and the ocean provides a spectacular coastline and fascinating habitats to explore. A myriad of marine plants and animals, including lacy red and slimy green algae, sluggish sea hares, leggy octopi, darting fish, and the always entertaining hermit crabs, live in this rocky intertidal area. Also on the west side of the park and just past the intertidal, but not yet reaching the horizon, visitors can see the imprints of the kelp forest on the ocean surface. This subtidal zone is an underwater forest with large kelp that provides food and shelter for some of the animals that live there: snails, urchins, abalone, sea stars, kelp bass, sheephead, and octopi. From December to March visitors can look beyond the kelp forest, toward the horizon, and see the Pacific Gray Whale pass by the shores on its annual migration from Alaska to Baja California, Mexico where it will birth and rear its young.